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1. In a differential amplifier, the CMRR is limited mostly by

a.CMRR of the op ampb.Gain-bandwidth productc.Supply voltagesd.Tolerance of resistors

ANSWER:D

2.Which of the following method used for biasing a BJT in integrated circuits isconsidered independent of transistor beta?

a.Fixed biasingb.Voltage divider biasc.Collector feedback biasd.Base bias with collector feedback

ANSWER: C

3.Guard driving reduces the

a.CMRR of an instrumentation amplifierb.Leakage current in the shielded cablec.Voltage gain of the first stage

d.Common-mode input voltage

ANSWER:C

4.An XOR gate produces an output only when its two inputs as

a.Highb.Lowc.Differentd.Same

ANSWER:C

5.The Howland current source produces a

a.Unidirectional floating load currentb.Bidirectional single-ended load currentc.Unidirectional single-ended load currentd.Bidirectional floating load current

ANSWER:B

6.With which of the following are step-up substations associated?

a.Concentrated loadb.Consumer location

c.Distributorsd.Generating stations

ANSWER:D

7.The purpose of AGC is to

a.Increase the voltage gain when the input signal increasesb.Convert voltage to currentc.Keep the output voltage almost constant

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d.Reduce the CMRR of the circuit

ANSWER:C

8.In an ac amplifier using an op amp with coupling and bypass capacitors, the output offset voltage is

a.Zerob.Minimumc.Maximumd.Unchanged

ANSWER:B

9.When we trim a resistor, we are

a.Making a fine adjustmentb.Reducing its valuec.Increasing its valued.Making a coarse adjustment

ANSWER:A10.Before illuminating a P-N junction photodiode, it has to be

a.Reverse-biasedb.Forward-biasedc.Switch ONd.Switch OFF

ANSWER:A

11.A D/A converter with four inputs has

a.Two outputsb.Four outputsc.Eight outputs

d.Sixteen outputs

ANSWER:D

12.An ideal op-amp has

a.Infinite Avb.Infinite Ric.Zero Rod.All of the above

ANSWER:D

13.When a JFET is used in an AGC circuit, it acts like a

a.Switchb.Voltage-controlled current sourcec.Voltage-controlled resistanced.Capacitance

ANSWER:C

14.In _______method of starting three phase induction motors the starting voltag

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e is not reduced.

a.Auto-transformerb.Star- deltac.Slip ringd.Any of the above

ANSWER:C

15.If an op amp has only a positive supply voltage, its output cannot

a.Be negativeb.Be zeroc.Equal the supply voltaged.Be ac coupled

ANSWER:A

16.Floating neutral, in 3-phase supply, is undesirable because it causes

a.Low voltage across the loadb.High voltage across the loadc.Unequal line voltage across the loadd.None of the above

ANSWER:C

17.The center frequency of a frequency of a bandpass filter is always equal to

a.The bandwidthb.Geometric average of the cutoff frequenciesc.Bandwidth divided by Qd.3-dB frequency

ANSWER:B

18.Skin effect is proportional to

a.(Conduction diameter)^4b.(Conduction diameter)^3c.(Conduction diameter)^2d.(Conduction diameter)^1/2

ANSWER:C

19.The Q of narrowband filter is always

a.Smallb.Equal to BW divided by f0c.Less than 1

d.Greater than 1

ANSWER:D

20.A bandstop filter is sometimes called a

a.Snubberb.Phase shifterc.Notch filterd.Time delay circuit

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ANSWER:C

21.The all pass filter has

a.No passbandb.One stopbandc.The same gain at all frequenciesd.A fast rolloff above cutoff

ANSWER:C

22.A unijunction transistor has

a.Anode, cathode and a gateb.Two bases and one emitterc.Two anodes and one gated.Anode, cathode and two gates

ANSWER:B

23.The approximation with a maximally-flat passband is

a.Chebyshev

b.Inverse chebyshevc.Ellipticd.Bessel

ANSWER: B

24.A DE-MOSFET differs from a JFET in the sense that it has no

a.Channelb.Gatec.P-N junctionsd.Substrate

ANSWER:C

25. If a filter has six second-order stages and one first-order stage, the orderis

a.2b.6c.7d.13

ANSWER:D

26. Monolithic ICs are

a.Forms of discrete circuitsb.On a single chipc.Combinations of thin-film and thick-film circuitsd.Also called hybrid ICs

ANSWER:B

27.If a butterworth filter has 9 second-order stages, its rolloff rate is

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a.20 dB per decadeb.40 dB per decadec.180 dB per decaded.360 dB per decade

ANSWER:D

28.When the reverse bias voltage of a varactor diode increases, its

a.Capacitance decreasesb.Leakage current decreasesc.Negative resistance increasesd.Depletion zone decreases

ANSWER:A

29.The filter with the slowest roll-off rate is the

a.Butterworthb.Chebyshevc.Ellipticd.Bessel

ANSWER:D

30.If any capacitors is open, the ac output voltage will

a.Decreaseb.Increasec.Remain the samed.Equal zero

ANSWER:A

31.Salllen-key filters are also called

a.VCVS filters

b.MFB filtersc.Biquadratic filtersd.State-variable filters

ANSWER:A

32.In a transistor amplifier, the reverse saturation current Ico

a.Doubles for every 10 degrees C rise in temperatureb.Doubles for every 1 degrees C rise in temperaturec.Increases linearly with the temperatured.Doubles for every 5 degrees C rise in temperature

ANSWER:A

33.To build a 10th order filter, we should cascade

a.10 first-stage stagesb.5 second-order stagesc.3 third-order stagesd.2 fourth-order stages

ANSWER:B

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34.A 1 microsecond pulse can be converted into a 1ms pulse by using

a.A monostable multivibratorb.An astable multivibratorc.A bisatable multivibratord.A J-K flip-flop

ANSWER: A

35.The Q of a Sallen-key second-order stage depends on the

a.Voltage gainb.Center frequencyc.Bandwidthd.GBW of the op amp

ANSWER: A

36.The main job of a voltage regulator is to provide a nearly ____ output voltage.

a.Sinusoidalb.Constant

c.Smoothd.fluctuation

ANSWER: B

37.With Sallen-key high-pass filters, the pole frequency must be

a.Added to the K valuesb.Subtracted from the K valuesc.Multiplied by the K valuesd.Divided by the K values

ANSWER: d

38.The following is not a sequential circuit

a.J-K flip flopb.Counterc.Full adderd.Shift register

ANSWER: c

39.A second-order all pass filter can vary the output phase from

a.90 degrees to -90 degrees

b.0 degrees to -180 degreesc.0 degrees to -360 degreesd.0 degrees to -720 degrees

ANSWER: C

40.A wound rotor induction motor is preferred, as compared to squirrel cage induction motor, when major consideration is

a.Slope speed operation

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b.High starting torquec.Low windage lossesd.All of the above

ANSWER: B

41. In a nonlinear op-amp circuit, the

A. Op amp never saturatesB. Feedback loop is never openedC. Output shape is the same as the input shapeD. Op amp may saturate

ANSWER: D

42. A transistor is operated as a non-saturated switch to eliminate

A. storage timeB. turn-off timeC. turn-on timeD. delay time

ANSWER: A

43. The voltage out of a Schmitt trigger is

A. A low voltageB. A high voltageC. Either a low or a high voltageD. A sine wave

ANSWER: C

44. A signal may have frequency components which lie in the range of 0.001 Hz to10 Hz. Which one of the following types of couplings should be chosen in a multistage amplifier designed to amplify this signal?

A. RC couplingB. Transformer couplingC. Direct couplingD. Double-tuned transformer

ANSWER: C

45. Hysteresis prevents false triggering associated with

A. A sinusoidal inputB. Noise voltagesC. Stray capacitancesD. Trip points

ANSWER: B

46. The resolution of a logic analyzer is

A. Maximum number of input channelsB. The minimum duration of the glitch it can captureC. Its internal clock periodD. The minimum amplitude of the input signal it can display

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ANSWER: A

47. If the input is a rectangular pulse, the output of an integrator is a

A. Sine waveB. Square waveC. RampD. Rectangular pulse

ANSWER: C

48. The most obvious identifying feature of a TTL gate is its

A. large fan-outB. high power dissipationC. interconnected transistorsD. multi-emitter transistor

ANSWER: D

49. When a large sine wave drives a Schmitt trigger, the output is a

A. Rectangular waveB. Triangular wave

C. Rectified sine waveD. Series of ramps

ANSWER: A

50. Regenerative braking

A. can be used for stopping a motorB. cannot be easily applied to dc series motorsC. can be easily applied to dc shunt motorsD. cannot be used when motor load has overhauling characteristics

ANSWER: C

51. The output of a relaxation oscillator is a

A. Sine waveB. Square waveC. RampD. Spike

ANSWER: B

52. The device possessing the highest sensitivity is a

A. Photoconductive cell

B. Photovoltaic cellC. PhotodiodeD. Phototransistor

ANSWER: D

53. If AOL=200,000, the closed-loop knee voltage of a silicon diode is

A. 1 microVoltB. 3.5 microVolt

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C. 7 microVoltD. 14 microVolt

ANSWER: B

54. For the operation of enhancement only N-channel MOSFET, value gate voltage has to be

A. high positiveB. high negativeC. low positiveD. zero

ANSWER: A

55. The input to a peak detector is a triangular wave with a peak-to-peak valueof 8 V and an average value of 0. The output is

A. 0B. 4 VC. 8 VD. 16 V

ANSWER: B

56. A PIN diode is frequently used as a

A. peak clipperB. voltage regulatorC. harmonic generatorD. switching diode for frequencies up to GHz range

ANSWER: D

57. To work properly, many IC comparators need an external

A. Compensating capacitor

B. Pullup resistorC. Bypass circuitD. Output stage

ANSWER: B

58. The voltage between the input terminals of an ideal op amp is

A. ZeroB. Very smallC. Very largeD. Equal to the input voltage

ANSWER: A

59. A Schmitt trigger

A. Is a zero-crossing detectorB. Has two trip pointsC. Produces triangular output wavesD. Is designed to trigger on noise voltage

ANSWER: B

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60. If a change in base current does not change the collector current, the transistor amplifier is said to be

A. saturatedB. cut-offC. criticalD. complemented

ANSWER: A

61. The trip point of a comparator is the input voltage that causes

A. The circuit to oscillateB. Peak detection of the input signalC. The output to switch statesD. Clamping to occur

ANSWER: C

62. In an ideal transformer

A. windings have no resistanceB. core has no losses

C. core has infinite permeabilityD. all of the above

ANSWER: D

63. An active half-wave rectifier has a knee voltage of

A. 7VB. 0.7 VC. More thn 0.7 VD. Much less than 0.7 V

ANSWER: D

64. CMOS circuits are extensively used for on-chip computers mainly because of their extremely

A. low power dissipationB. large packing densityC. high noise immunityD. low cost

ANSWER: B

65. In an active peak detector, the discharging time constant is

A. Much longer than the periodB. Much shorter than the periodC. Equal to the periodD. The same as the charging time constant

ANSWER: A

66. The 2's complement of 1000 base 2 is

A. 0111

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B. 0101C. 1000D. 0001

ANSWER: C

67. The positive clamper adds

A. A positive dc voltage to the inputB. A negative dc voltage to the inputC. An ac signal to the outputD. A trip point to the input

ANSWER: A

68. Solar cells are used as source of power in earth satellites because they have

A. very high efficiencyB. unlimited lifeC. high power capacity per weightD. both A and B

ANSWER: D

69. An oscillator always needs an amplifier with

A. Positive feedbackB. Negative feedbackC. Both types of feedbackD. An LC tank circuit

ANSWER: A

70. Darlington pairs are frequently used in linear ICs because they

A. do not require any capacitors or inductors

B. have enormous impedance transformation capabilityC. can be readily formed from two adjacent transistorsD. resemble emitter followers

ANSWER: C

71. The voltage that starts an oscillator is caused by

A. Ripple from the power supplyB. Noise voltage in resistorsC. The input signal from a generatorD. Positive feedback

Answer: B

72. GaAs, LEDs emit radiation in the

A. ultraviolet regionB. violet-blue green range of the visible regionC. visible regionD. infrared regionAnswer: D

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73. A coupling circuit is a

A. Lag circuitB. Lead circuitC. Lead-lag circuitD. Resonant circuitAnswer: B

74. The IP/IV ratio of a tunnel diode is of primary importance in

A. determining tunneling speed of electronB. the design of an oscillatorC. amplifier designingD. computer applicationsAnswer: D

75. A lead circuit has a phase angle that is

A. Between 0 and +90 degreesB. Greater than 90 degreesC. Between 0 and -90 degrees

D. The same as the input voltageAnswer: A

76. A one-shot is a type of

A. monostablemultivibratorB. astablemultivibratorC. bistablemultivibratorD. timerAnswer: A

77. Initially, the loop gain of a Wien-bridge oscillator is

A. 0B. 1C. LowD. HighAnswer: D

78. For which of the following applications motor has to start with high acceleration?

A. Oil expeller

B. Floor millC. Lifts and hoistsD. Centrifugal pumpAnswer: C

79. For oscillations to start in a circuit, the loop gain must be greater than 1when the phase shift around the loop is

A. 90

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B. 180C. 270D. 360Answer: D

80. The minimum value of current required to maintain conduction in an SCR is called its __________ current.

A. CommutationB. HoldingC. Gate triggerD. BreakoverAnswer: B

81. A 741C has supply voltages of plus and minus 15 V. If the load resistance islarge, the MPP value is

A. 0B. +15 VC. 27 VD. 30 V

Answer: C

82. The most widely used LC oscillator is the

A. ArmstrongB. ClappC. ColpittsD. HartleyAnswer: C

83. When a BJT is employed as an amplifier, it operates

A. in cut-offB. in saturationC. well into saturationD. over the active regionAnswer: D

84. When Q decreases in a Colpitts oscillator, the frequency of oscillation

A. DecreasesB. Remains the sameC. IncreasesD. Becomes erratic

Answer: A

85. The two input terminals of an OP-AMP are known as

A. positive and negativeB. differential and non-differentialC. inverting and non-invertingD. high and low

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Answer: C86. Link coupling refers to

A. Capacitive couplingB. Transformer couplingC. Resistive couplingD. Power couplingAnswer: B.

87. A class B push-pull amplifier has the main advantage of being free from

A. any circuit imbalancesB. unwanted noiseC. even-order harmonic distortionD. dc magnetic saturation effectsAnswer: C.88. To vary the frequency of an LC oscillator, you can vary

A. One resistorB. Two resistorsC. Three resistorsD. One capacitor

Answer: D.

89. Which of the following equipment is used to limit short-circuit current level in a substation?

A. IsolatorB. Two resistorsC. Three resistorsD. One capacitorAnswer: D

90. The kind of oscillator found in an electronic wristwatch is the

A. ArmstrongB. ClappC. ColpittsD. Quartz crystalAnswer: D.

91. A phototransistor excels a photodiode in the matter of

A. faster switchingB. greater sensitivity

C. higher current capacityD. both B and CAnswer: D

92. An astable 555 timer has the following number of stable states:

A. 0B. 1C. 2

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D. 3Answer: A

93. The basic reason why a FW rectifier has twice the efficiency of a HW rectifier is that

A. it makes use of a transformerB. its ripple factor is much lessC. it utilizes both half-cycle of the inputD. its output frequency is doubled the line frequencyAnswer: C

94. The output waveform of a 555 timer is

A. sinusoidalB. triangularC. rectangularD. ellipticalAnswer: C

95. In positive logic, logic state 1 corresponds to

A. Positive voltageB. Higher voltage levelC. Zero voltage levelD. Lower voltage levelAnswer: B

96. Voltage regulators normally use

A. Negative feedbackB. Positive feedbackC. No feedback

D. Phase limitingAnswer: A

97. The unique characteristics of LASER light are that is

A. coherentB. monochromaticC. collimatedD. all of the aboveAnswer: D

98. Without current limiting, a shorted load will probably

A. Produce zero load currentB. Destroy diodes and transistorsC. Have a load voltage equal to the zener voltageD. Have too little load currentAnswer: B

99. In a rectifier, the larger the value of shunt capacitor filter

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A. larger the p-p value of ripple filterB. larger the peak current in the rectifying diodeC. longer the time that current pulse flows through the diodeD. small the dc voltage across the loadAnswer: B

100. A flip-flop which can have an uncertain output state is:

A. J-K flip-flopB. S-C flip-flopC. D flip-flopD. T flip-flopAnswer: B